如何创建此查询 [英] how to create this query

问题描述

如何创建查询，如果我需要在选择行中包括两个聚合函数，并且每个函数我需要不同的分组依据以及在我的示例中条件
需要返回的playerName，以及多少个玩家能否赢得此奖金，可以先检查桌面游戏的结果是否为result =首先，以及他玩过多少次

how to create a query if i need to include two aggregate function in select row and per each function i need different group by and where conditions in my example i need to returns the playerName, and how many the player win the this can be checked if the results in table game result= first, and how many times he played

，但不知道如何处理两个聚合函数。

but do not know how to deal with two aggregate functions .

我只想加入这两个查询的结果

simply i want to join the result of this two queries

1。

select playeName,count(*)
from  player,game
where player.playerId=game.playerId and result="first"
group by game.playerId

2。

select count(*)
from game, player
where game.playerId=player.playerId
group by game.playerId

桌面游戏的属性集为
playerId，结果
的属性为牌桌玩家是
玩家e，playerId

the set of attributes for table game are playerId , result the set of attributes for table player are playerName,playerId

任何想法？

推荐答案

使用：

  SELECT p.playername,
         SUM(CASE WHEN g.result = 'first' THEN 1 ELSE 0 END),
         COUNT(*)
    FROM PLAYER p
    JOIN GAME g ON g.playerid = p.playerid
GROUP BY p.playername

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